Develop Reference

How to use a service account to authorize google sheets?

I am trying to open a private google sheet using python. The end goal here is to read that private sheet data into a json object. I have made sure to create a google cloud project, enable the API's, and service account. The service account email has been shared and added as an editor. I also created OAuth keys for a desktop application. This is required since the file is private.
I know I need to somehow request a token to use for access to the sheets API, but I am at a loss for how to create a request, and utilize the client_secret file generated from OAuth keys. I figured the googleAPI would have a function where you can pass this file directly, but I am lost in documentation.
Any insight would be appreciated!

All you need to do is supply the library with the location of the clientSecret.json file you should have downloaded from Google cloud console. This method should build the service for you and you can make the requests to the api. It will handle all the authorization.
from apiclient.discovery import build
from oauth2client.service_account import ServiceAccountCredentials
def get_service(api_name, api_version, scopes, key_file_location):
"""Get a service that communicates to a Google API.
Args:
api_name: The name of the api to connect to.
api_version: The api version to connect to.
scopes: A list auth scopes to authorize for the application.
key_file_location: The path to a valid service account JSON key file.
Returns:
A service that is connected to the specified API.
"""
credentials = ServiceAccountCredentials.from_json_keyfile_name(
key_file_location, scopes=scopes)
# Build the service object.
service = build(api_name, api_version, credentials=credentials)
return service
The best example I know of for service account authentication with python is the Google analytics quickstart If you have any issues altering it for google sheets let me know i can try and help.
Calling it should be something like this.
def main():
# Define the auth scopes to request.
scope = 'https://www.googleapis.com/auth/spreadsheets'
key_file_location = '<REPLACE_WITH_JSON_FILE>'
# Authenticate and construct service.
service = get_service(
api_name='sheets',
api_version='v4',
scopes=[scope],
key_file_location=key_file_location)
data = your_method_to_call_sheets(service)
How to create clientSecret.json remember to enable the google sheets api under libary

How to get a GCP Bearer token programmatically with python

gcloud auth print-access-token gives me a Bearer token that I can use later on; however, this is a shell command. How would I obtain one programmatically via the Google Cloud Python API?
I see a prior example using oauth2client, but oauth2client is now deprecated. How would I do this with google.auth and oauthlib?

While the above answer is quite informative, it misses one important point - credentials object obtained from google.auth.default() or compute_engine.Credentials() will not have token in it. So back to the original question of what is the programmatic alternative to gcloud auth print-access-token, my answer would be:
import google.auth
import google.auth.transport.requests
creds, project = google.auth.default()
# creds.valid is False, and creds.token is None
# Need to refresh credentials to populate those
auth_req = google.auth.transport.requests.Request()
creds.refresh(auth_req)
# Now you can use creds.token
I'm using the official google-auth package and default credentials, which will get you going both in local dev and on remote GCE/GKE app.
Too bad this is not properly documented and I had to read google-auth code to figure our how to obtain the token.

The answer depends on your environment and how you want to create / obtain credentials.
What are Google Cloud Credentials?
Google Cloud credentials are an OAuth 2.0 token. This token has at a minimum an Access Token and optionally a Refresh Token, Client ID Token, and supporting parameters such as expiration, Service Account Email or Client Email, etc.
The important item in Google Cloud APIs is the Access Token. This token is what authorizes access to the cloud. This token can be used in programs such as curl, software such as python, etc and does not require an SDK. The Access Token is used in the HTTP Authorization header.
What is an Access Token?
An access token is an opaque value generated by Google that is derived from a Signed JWT, more correctly called JWS. A JWT consists of a header and claims (the payload) Json structures. These two Json structures are signed with the Service Account's Private Key. These values are base64 encoded and concatenated to create the Access Key.
The format of an Access Token is: base64(header) + '.' + base64(payload) + '.' + base64(signature).
Here is an example JWT:
Header:
{
"alg": "RS256",
"typ": "JWT",
"kid": "42ba1e234ac91ffca687a5b5b3d0ca2d7ce0fc0a"
}
Payload:
{
"iss": "myservice#myproject.iam.gserviceaccount.com",
"iat": 1493833746,
"aud": "myservice.appspot.com",
"exp": 1493837346,
"sub": "myservice#myproject.iam.gserviceaccount.com"
}
Using an Access Token:
Example that will start a VM instance. Replace PROJECT_ID, ZONE and INSTANCE_NAME. This example is for Windows.
curl -v -X GET -H "Authorization: Bearer <access_token_here>" ^
https://www.googleapis.com/compute/v1/projects/%PROJECT_ID%/zones/%ZONE%/instances/%INSTANCE_NAME%/start
Compute Engine Service Account:
Dustin's answer is correct for this case, but I will include for completeness with some additional information.
These credentials are automatically created for you by GCP and are obtained from the VM Instance metadata. Permissions are controlled by Cloud API access scopes in the Google Console.
However, these credentials have some limitations. To modify the credentials you must stop the VM Instance first. Additionally, not all permissions (roles) are supported.
from google.auth import compute_engine
cred = compute_engine.Credentials()
Service Account Credentials:
Until you understand all of the types of credentials and their use cases, these are the credentials that you will use for everything except for gcloud and gsutil. Understanding these credentials will make working with Google Cloud much simpler when writing programs. Obtaining credentials from a Google Service Account Json file is easy. The only item to make note of is that credentials expire (typically 60 minutes) and either need to be refreshed or recreated.
gcloud auth print-access-token is NOT recommended. Service Account Credentials are the recommended method by Google.
These credentials are created by the Console, gcloud or via programs / APIs. Permissions are assigned to the creditials by IAM and function inside Compute Engine, App Engine, Firestore, Kubernetes, etc. as well as other environments outside of Google Cloud. These credentials are downloaded from Google Cloud and stored in a Json file. Notice the scopes parameter. This defines permissions that are granted to the resulting credentials object.
SCOPES = ['https://www.googleapis.com/auth/sqlservice.admin']
SERVICE_ACCOUNT_FILE = 'service-account-credentials.json'
from google.oauth2 import service_account
cred = service_account.Credentials.from_service_account_file(
SERVICE_ACCOUNT_FILE, scopes=SCOPES)
Google OAuth 2.0 Credentials:
These credentials are derived from a full OAuth 2.0 flow. These credentials are generated when your browser is launched to access Google Accounts for authorizing access. This process is much more complicated and requires a fair amount of code to implement and requires a built-in web server for the callback for authorization.
This method provides additional features such as being able to run everything in a browser, example you can create a Cloud Storage File Browser, but be careful that you understand the security implications. This method is the technique used to support Google Sign-In, etc. I like to use this method to authenticate users before allowing posting on websites, etc. The possibilities are endless with correctly authorized OAuth 2.0 identities and scopes.
Example code using google_auth_oauthlib:
from google_auth_oauthlib.flow import InstalledAppFlow
flow = InstalledAppFlow.from_client_secrets_file(
'client_secrets.json',
scopes=scope)
cred = flow.run_local_server(
host='localhost',
port=8088,
authorization_prompt_message='Please visit this URL: {url}',
success_message='The auth flow is complete; you may close this window.',
open_browser=True)
Example code using the requests_oauthlib library:
from requests_oauthlib import OAuth2Session
gcp = OAuth2Session(
app.config['gcp_client_id'],
scope=scope,
redirect_uri=redirect_uri)
# print('Requesting authorization url:', authorization_base_url)
authorization_url, state = gcp.authorization_url(
authorization_base_url,
access_type="offline",
prompt="consent",
include_granted_scopes='true')
session['oauth_state'] = state
return redirect(authorization_url)
# Next section of code after the browser approves the request
token = gcp.fetch_token(
token_url,
client_secret=app.config['gcp_client_secret'],
authorization_response=request.url)

In some cases, it's not possible to set environment variables on the server or container while needing a Bearer access token to call Google cloud APIs. I present the following to solve such problem:
# pip3 install google-auth
# pip3 install requests
import google.auth
import google.auth.transport.requests
from google.oauth2 import service_account
credentials = service_account.Credentials.from_service_account_file('/home/user/secrets/hil-test.json', scopes=['https://www.googleapis.com/auth/cloud-platform'])
auth_req = google.auth.transport.requests.Request()
credentials.refresh(auth_req)
credentials.token
The last line would print the access token for calling Google cloud APIs. Replace ya29<REDACTED> in the following curl command with the printed token from python as a test:
curl https://example.googleapis.com/v1alpha1/projects/PROJECT_ID/locations -H "Authorization: Bearer ya29<REDACTED>"
It may not make sense to execute python to get the token then curl in BASH to call an API. The purpose is to demonstrate getting the token to call Google cloud Alpha API which may not have any Python client library but REST API. Developers can then use Python requests HTTP library to call the APIs.

import google.auth
import google.auth.transport.requests
# getting the credentials and project details for gcp project
credentials, your_project_id = google.auth.default(scopes=["https://www.googleapis.com/auth/cloud-platform"])
#getting request object
auth_req = google.auth.transport.requests.Request()
print(credentials.valid) # prints False
credentials.refresh(auth_req) #refresh token
#cehck for valid credentials
print(credentials.valid) # prints True
print(credentials.token) # prints token

This may not be the recommended way but for Rest API in my application this was an easy way to get the token.
from subprocess import PIPE, Popen
def cmdline(command):
process = Popen(
args=command,
stdout=PIPE,
shell=True
)
return process.communicate()[0]
token = cmdline("gcloud auth application-default print-access-token")
print("Token:"+token)

I found myself here when looking for a way to use the python SDK without creating a service account. I wanted a way to locally develop a script that would run in the cloud. I was able to achieve this by using an artifact of the gcloud command:
export GOOGLE_APPLICATION_CREDENTIALS=~/.config/gcloud/legacy_credentials/<me>/adc.json

Merging suggestions from this post and the google cloud documentation, I wrote an auxiliary function that returns a token. It generates a token if possible, and if not takes it from the environment, then checks that it's valid.
import google
import os
import requests
GOOGLE_APPLICATION_CREDENTIALS = "GOOGLE_APPLICATION_CREDENTIALS"
GCS_OAUTH_TOKEN = "GCS_OAUTH_TOKEN"
SCOPE = "https://www.googleapis.com/auth/cloud-platform"
URL = "https://www.googleapis.com/oauth2/v1/tokeninfo"
PAYLOAD = "access_token={}"
HEADERS = {"content-type": "application/x-www-form-urlencoded"}
OK = "OK"
def get_gcs_token():
"""
Returns gcs access token.
Ideally, this function generates a new token, requries that GOOGLE_APPLICATION_CREDENTIALS be set in the environment
(os.environ).
Alternatively, environment variable GCS_OAUTH_TOKEN could be set if a token already exists
"""
if GOOGLE_APPLICATION_CREDENTIALS in os.environ:
# getting the credentials and project details for gcp project
credentials, your_project_id = google.auth.default(scopes=[SCOPE])
# getting request object
auth_req = google.auth.transport.requests.Request()
credentials.refresh(auth_req) # refresh token
token = credentials.token
elif GCS_OAUTH_TOKEN in os.environ:
token = os.environ[GCS_OAUTH_TOKEN]
else:
raise ValueError(
f"""Could not generate gcs token because {GOOGLE_APPLICATION_CREDENTIALS} is not set in the environment.
Alternatively, environment variable {GCS_OAUTH_TOKEN} could be set if a token already exists, but it was not"""
)
r = requests.post(URL, data=PAYLOAD.format(token), headers=HEADERS)
if not r.reason == OK:
raise ValueError(
f"Could not verify token {token}\n\nResponse from server:\n{r.text}"
)
if not r.json()["expires_in"] > 0:
raise ValueError(f"token {token} expired")
return token

Official documentation code example
I followed this official documentation for Cloud Functions, which works for any GCP API:
auth_req = google.auth.transport.requests.Request()
id_token = google.oauth2.id_token.fetch_id_token(
auth_req,
# This is an OAuth authorisation scope that you must pass
# depending on the API.
# You can see an example of the need for this scope here: https://cloud.google.com/bigquery/docs/reference/rest/v2/jobs/insert#authorization-scopes
"https://www.googleapis.com/auth/bigquery"
)
Now, you can use id_token in the Authorisation header:
headers = {'Authorization': f'Bearer {id_token}'}

How to use the Google API without checking a client_secret.json into version control?

I'm working on a project in which, in accordance with https://12factor.net/config, we don't things like credentials in our code, but rather in environment variables.
I'm looking into using the Google Sheets API to collate some data from our database and put it into a Google sheet. Here is the partial example script from https://developers.google.com/sheets/api/quickstart/python:
from __future__ import print_function
from apiclient.discovery import build
from httplib2 import Http
from oauth2client import file as oauth_file, client, tools
# Setup the Sheets API
SCOPES = 'https://www.googleapis.com/auth/spreadsheets.readonly'
store = oauth_file.Storage('token.json')
creds = store.get()
if not creds or creds.invalid:
flow = client.flow_from_clientsecrets('credentials.json', SCOPES)
creds = tools.run_flow(flow, store)
service = build('sheets', 'v4', http=creds.authorize(Http()))
Firstly, it is not clear to me from the documentation what 'token.json' and 'credentials.json' should be in this example. From the API console, in the Credentials tab, I downloaded a client_secret_<long suffix>.json which looks like this:
{"installed":{"client_id":"[our_client_id]","project_id":"nps-survey-1532981793379","auth_uri":"https://accounts.google.com/o/oauth2/auth","token_uri":"https://accounts.google.com/o/oauth2/token","auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs","client_secret":"[our_client_secret]","redirect_uris":["urn:ietf:wg:oauth:2.0:oob","http://localhost"]}}
Should this JSON file be the 'token.json' in this example, or the 'credentials.json'? Also, is there a way to instantiate valid creds by specifying the client secret and client ID directly, and not using this JSON file?

I ended up going through the OAuth 2.0 setup for a web application instead of an installed application, and using google_auth_oauthlib. The Flow object has a class method from_client_config() which can be used like so (cf. https://developers.google.com/identity/protocols/OAuth2WebServer):
from django.conf import settings
from django.shortcuts import redirect
import google.oauth2.credentials
import google_auth_oauthlib.flow
# Client configuration for an OAuth 2.0 web server application
# (cf. https://developers.google.com/identity/protocols/OAuth2WebServer)
CLIENT_CONFIG = {'web': {
'client_id': settings.GOOGLE_CLIENT_ID,
'project_id': settings.GOOGLE_PROJECT_ID,
'auth_uri': 'https://accounts.google.com/o/oauth2/auth',
'token_uri': 'https://www.googleapis.com/oauth2/v3/token',
'auth_provider_x509_cert_url': 'https://www.googleapis.com/oauth2/v1/certs',
'client_secret': settings.GOOGLE_CLIENT_SECRET,
'redirect_uris': settings.GOOGLE_REDIRECT_URIS,
'javascript_origins': settings.GOOGLE_JAVASCRIPT_ORIGINS}}
# This scope will allow the application to manage your calendars
SCOPES = ['https://www.googleapis.com/auth/calendar']
def get_authorization_url():
# Use the information in the client_secret.json to identify
# the application requesting authorization.
flow = google_auth_oauthlib.flow.Flow.from_client_config(
client_config=CLIENT_CONFIG,
scopes=SCOPES)
# Indicate where the API server will redirect the user after the user completes
# the authorization flow. The redirect URI is required.
flow.redirect_uri = 'http://localhost:8000'
# Generate URL for request to Google's OAuth 2.0 server.
# Use kwargs to set optional request parameters.
authorization_url, state = flow.authorization_url(
# Enable offline access so that you can refresh an access token without
# re-prompting the user for permission. Recommended for web server apps.
access_type='offline',
# Enable incremental authorization. Recommended as a best practice.
include_granted_scopes='true')
return authorization_url, state
The settings attributes are, in turn, generated by calling os.getenv() for each corresponding attribute. In this way, the configuration can be obtained from environment variables instead of a local file.

How to log in as different user to Google API v3?

So I'm trying to create a new calendar, but i want to be able to specify what google account to create it in, assuming i have the credentials for said account, which i do. The code bellow creates it on the currently signed in user, or requires user interaction to allow access. Is there a way to specify an user and run the command on the background. I essentially just want to add a calendar to my account when the program runs, but i cant guarantee that my account will be logged in at the time.
I believe this was possible with the version 2 of the google api through ClientLogin, but i'm trying to use version 3.
import gflags
import httplib2
from apiclient.discovery import build
from oauth2client.file import Storage
from oauth2client.client import OAuth2WebServerFlow
from oauth2client.tools import run
FLAGS = gflags.FLAGS
FLOW = OAuth2WebServerFlow(
client_id='MY_CLIENT_KEY',
client_secret='MY_CLIENT_SECRET',
scope='https://www.googleapis.com/auth/calendar',
user_agent='MyApp/v1')
storage = Storage('calendar.dat')
credentials = storage.get()
if credentials is None or credentials.invalid == True:
credentials = run(FLOW, storage)
http = httplib2.Http()
http = credentials.authorize(http)
service = build(serviceName='calendar', version='v3', http=http)
calendar = {
'summary': 'Test3',
'timeZone': 'America/New_York'
}
created_calendar = service.calendars().insert(body=calendar).execute()

With V3, you'll need to use a Service Account in order to act as the user. The process is described in the Google Drive documentation, you just need to use Calendar API v3 scopes and references instead of Google Drive API.

Another option would be to store the OAuth2 refresh token and use it to grab valid access tokens even if the user is not logged in. See my reply to google Calendar api v3 Auth only for first time

Google Contact API - Auth2.0

I'm looking for a good way to retrieve every emails address of my contacts from a google account for a "desktop" application in Python.
In a first time, I created an app via Google Code. I toggled Google Plus API, retrieving most of my user data, but not any of my contacts.
I started investigate, and I found a lot of stuff, but most of them was outdated.
I found a good way to retrieve my contacts, using gdata library but granting me a full read/write access on it, via https://www.google.com/m8/feeds with no feedback.
self.gd_client = gdata.contacts.client.ContactsClient(source='MyAppliName')
self.gd_client.ClientLogin(email, password, self.gd_client.source)
According to the official 'google contact api' google group, which migrated to stackoverflow, read only access is broken.
By the way, I'm not a huge fan of 'Trust my application, I use read only access, I swear."
I found the google api playground at https://developers.google.com/oauthplayground in which they use OAuth2.0 token with most of apis, including contact, toggling a webpage:
Google OAuth 2.0 Playground is requesting permission to:
Manage your contacts
According to this playground, it's possible to use OAuth2.0 with google contact api, but I have no idea how to add https:// www.google.com/m8/feeds to my scope, which doesn't appear on the list.
Is there an other way to do that ?

If this question is still open for you, here is some sample code how to use oauth2 and Google Contact API v3:
import gdata.contacts.client
from gdata.gauth import AuthSubToken
from oauth2client import tools
from oauth2client.client import flow_from_clientsecrets
from oauth2client.file import Storage
def oauth2_authorize_application(client_secret_file, scope, credential_cache_file='credentials_cache.json'):
"""
authorize an application to the requested scope by asking the user in a browser.
:param client_secret_file: json file containing the client secret for an offline application
:param scope: scope(s) to authorize the application for
:param credential_cache_file: if provided or not None, the credenials will be cached in a file.
The user does not need to be reauthenticated
:return OAuth2Credentials object
"""
FLOW = flow_from_clientsecrets(client_secret_file,
scope=scope)
storage = Storage(credential_cache_file)
credentials = storage.get()
if credentials is None or credentials.invalid:
# Run oauth2 flow with default arguments.
credentials = tools.run_flow(FLOW, storage, tools.argparser.parse_args([]))
return credentials
SCOPES = ['https://www.google.com/m8/feeds/', 'https://www.googleapis.com/auth/userinfo.email']
credentials = oauth2_authorize_application('client-secret.json', scope=SCOPES)
token_string = credentials.get_access_token().access_token
# deprecated!
# auth_token = AuthSubToken(token_string, SCOPES)
with open('client-secret.json') as f:
oauth2_client_secret = json.load(f)
auth_token = gdata.gauth.OAuth2Token(
client_id=oauth2_client_secret['web']['client_id'],
client_secret=oauth2_client_secret['web']['client_secret'],
scope=SCOPES,
user_agent='MyUserAgent/1.0',
access_token=credentials.get_access_token().access_token,
refresh_token=credentials.refresh_token)
client = gdata.contacts.client.ContactsClient(auth_token=auth_token)
query = gdata.contacts.client.ContactsQuery()

The request should look like:
https://accounts.google.com/o/oauth2/auth?
scope=https%3A%2F%2Fwww.google.com%2Fm8%2Ffeeds&
state=<myState>&
redirect_uri=<Redirect URI>&
response_type=code&
client_id=<my Client ID>&approval_prompt=force
This will obtain read/write access to the user's contacts.